It is known from the literature (J. Mitola, “The Software Radio Architecture”, IEEE Communications Magazine, May 1995 and E. Buracchini, “The Software Radio Concept”, IEEE Communications Magazine, September 2000) that reconfigurable systems like terminals, base stations and network nodes, are equipments whose operating working may be reconfigured at will. For instance, a reconfigurable radio terminal able to work with a second generation system (2G), like GSM/GPRS (Global System for Mobile communication/General Packet Radio Service), can be reconfigured in order to become able to work with a third generation system (3G), like UMTS (Universal Mobile Telecommunication System) or CDMA 2000 (Code Division Multiple Access 2000), or WI-FI (WIreless FIdelity) or DVB-T (Digital Video Broadcasting Terrestrial) systems and so on.
It is meant by “system” a plurality of elements co-ordinated between them according to predetermined criteria, that is co-ordinated according to a “Standard”, in order to perform a specific function which is, for instance, that of operating as a communication network.
In present document examples of systems are the GSM system, the GPRS system, the UMTS system, the WLAN (Wireless Local Area Network) system and so on, each of them complying with a corresponding Standard.
In order to carry out the reconfiguration of a terminal, it is necessary that the operative functions of the terminal are realised with a technology which is in turn reconfigurable. Concerning this, the reconfigurable terminals or devices are provided with a reprogrammable hardware constituted, for example, by a plurality of FPGAs (Field Programmable Gate Array), DSPs (Digital Signal Processor) and microprocessors: the single functionalities of the device, even at the lowest level, are performed by a software code. As a consequence, for reconfiguring a reprogrammable device, it suffices to replace the operating software managing the hardware of the device itself.
By the term “operating software” it is meant in present description the software, organised in libraries, which defines both the radio interface or lower layers (e.g. L1, L2, L3) and the upper layers (e.g. L4 up to L7) of the protocol stack of a considered system, like for instance GSM/GPRS, UMTS and so on.
As known, in the telecommunication domain, the most employed method for obtaining a functional grouping is the OSI model (Open System Interconnection). The functionalities are grouped in functional planes or layers represented under the form of a stack of layers.
Each layer provides services to the immediately higher layer, said services being in turn improvements of the services provided by the immediately lower layer.
The lowest layer (layer 1) is generally intended for physically transmitting the information.
According to the OSI specification, the standard number of layers is 7: respectively physical, connection, network, transport, session, presentation and application layer. Each system, e.g. GSM/GPRS, UMTS and so on, implements the necessary part of said standard stack.
When considering a radio terminal, the benefits provided when using a reconfigurable hardware are many, but one benefit is evidently immediate: the radio terminal can be reconfigured according to the system covering the area where the terminal is located (working area). Therefore, if the terminal is used in an area covered by a second generation system, like GSM/GPRS, the terminal can be configured in order to be able to receive said system; likewise, in an area covered by a third generation system, like UMTS, the terminal can be configured accordingly.
It is known that a software code may be transferred or downloaded to a terminal at least in three different ways:                via a smart card by using a SIM (Subscriber Identity Module) to be inserted inside the radio mobile terminal;        via an external connection by using for instance a link with a personal computer through an infrared/serial/USB port;        via radio or over-the-air (OTA) by using a specific radio channel.        
Concerning software downloading, the fundamental steps of a generic protocol allowing to manage the downloading of a software to a terminal have been defined in the framework of the Software Defined Radio Forum (SDR Forum) as reachable via the URL: www.sdrforum.org.
The protocol, as defined by SDR Forum, is of the client-server type.
The downloading protocol steps are the following ones:                download initiation: step during which the terminal communicates to the server, on which a software to be downloaded is resident, the intention to begin a software download;        mutual authentication; the terminal and the server authenticate each other;        capability exchange: the server communicates the capability information relative to the software to be downloaded and the terminal verifies whether the software can be loaded into the terminal memory, installed therein and run;        download acceptance: the server communicates to the terminal the downloading, installation and billing options; the terminal decides whether the indications provided by the server are acceptable or not;        download and integrity test: during the software download, the received code is tested; the terminal requests the retransmission of the incorrectly received radio blocks;        installation: during the installation step, the software billing and licensing conditions are provided by the server;        in-situ testing: before starting the software, the terminal carries out some tests with the help of test vectors downloaded together with the software code;        non repudiation exchange: once the software code has been installed and tested, the terminal confirms to the server that the installation was successful in order to start, for example, the billing procedure.        
It is known from prior art, e.g. E. Buracchini, “The Software Radio Concept”, IEEE Communications Magazine, September 2000, that the software downloading via radio or OTA foresees the use by the terminal of a radio channel. Moreover it is known that the download of software code can be done in two different ways, depending on the typology of the radio channel:                “out of band” way: by means of a “universal” channel independent from the current system, e.g. when the terminal is switched on, it automatically tunes to said channel and performs the download of the operating software relative to the system operating in the working area;        “in band” way: by using the radio channels of the standard cellular systems of second and third generation, like GSM/GPRS and UMTS respectively, this way provides that the terminal, already operating on one of these channels, receives the operating software relative to a system different from that currently used; for instance, a reconfigurable terminal operating with a second generation system, like GSM/GPRS, can perform the download of a third generation system, like UMTS, by using the second generation radio channel according to which it is working.        
An example of “out of band” software download is for instance described in the Japanese Patent Application No. 2001061186. This document describes a system and a method for downloading software content over-the-air. When a radio terminal is switched on, it seeks on an universal channel what the current system in the working area is and carries out the software download relative to the indicated system.
An example of “in band” software download is for instance described in the US Patent Application No. 2003/0163551. This document describes a system and a method for downloading software over-the-air by using:                dedicated channels during the negotiation steps between server and terminal (capability exchange, authentication, billing and so on), and        shared common channels during the download procedure in order to provide the download service to as many users as possible simultaneously, without imposing a handicap on the available radio resources.        
When considering the “in band” download way, the document AAVV, “Architecture of IP based Network Elements Supporting Reconfigurable Terminals”, SCOUT Workshop 16 Sep. 2003 suggests to modify deeply some protocols and some network nodes, e.g. the radio access nodes and/or Core Networks nodes, in order to make it possible to manage the download of an operating software.
Such modifications imply a considerable effort for the equipment manufacturers and for the network operators and dramatically impact on the Standards of the existing cellular systems. Therefore the known techniques exhibit the limit that, when it is desired to add to an already existing cellular network, like for instance GSM/GPRS or UMTS, the operating software download management for reconfigurable terminals, heavy modifications to the protocols and to the network nodes are necessary.
Considering the out of band way, according to prior art, it is needed to implement a dedicated radio channel and therefore dedicated network equipments or network nodes in the network for its implementation.
In summary, Applicant notes that known prior art both in case of in band and out of band software download provides for deeply modifying some protocols and some network nodes in order to configure a re-configurable radio terminal.